1. Field of the Invention
This invention relates to a selective call receiving apparatus capable of receiving selective call radio-wave signals, and receiving and indicating messages of the selective call signals.
2. Description of the Prior Art
In a prior art selective call receiving apparatus, received messages related to a common call (identification) number and a common function designation number are memorized in an order equal to the order of their reception or in an order determined by given priority. In other words, memorized messages related to a common call (identification) number and a common function designation number are not stored according to their types. Thus, in some cases, it takes a long time to search a memorized message of a desired type.
In a general selective calling system, when a message of one type is assigned to a combination of a call number and a function designation number, increasing the number of message types requires a receiver to have many call numbers. The receiver having many call numbers tends to be complicated in structure.
In an advanced selective calling system, message signals transmitted from a central station to receivers contain messages and also control signals of special patterns. In each of the receivers, received and memorized messages are stored in accordance with the control signals. The presence of a control signal increases a time of transmission of a related message signal. With respect to the handling of control signals of special patterns, it is necessary to previously provide complicated rules in the central station and the receivers.
U.S. Pat. No. 4,845,491 to Fascenda et al discloses a pager based information system used to transmit both conventional private messages (using unique pager IDs) and two types of unconventional multi-recipient (M-R) messages (using database IDs and group IDs), all using the conventional POCSAG pager transmission format. Operation of the pager is software controlled through the use of a microprocessor and a RAM. Authority to receive the M-R messages is provided at the time of manufacture (database IDs) or via broadcasts (group IDs). Database type M-R messages are stored in the pager RAM in a hierarchical or tree structure. The software controlled pagers permit the over-the-air modification of the operation of selected pagers, such as the addition or deletion of group IDs and the change in the tree structure of the storage area for the database messages. The pager includes a real time pager clock which is updated by pairs of broadcast time messages, the second having a time correlation for the first.
In the system of U.S. Pat. No. 4,845,491, an M-R syncword is followed by a line header code word including a line header. The line header has database ID bits for indicating the database, memory bank bits for designating which of banks of memory in the RAM is to be used, command bits for identifying the message which follows as a database message, a group message, an add/delete group ID message, or a set clock message, and database memory address bits for identifying the location in the RAM for database messages.
In the system of U.S. Pat. No. 4,845.491, the received codes specify processing a code as either a database message, a group message, a change group message, and a time message, each having its own corresponding address area.
U.S. Pat. No. 5,049,874 to Ishida et al discloses a paging receiver including a receiver main body and a card-like ROM. The receiver main body includes a receiver circuit for receiving a paging signal, reception controllers for ON/OFF containing the receiving circuit on the basis of reception control data, address comparators for checking whether a calling signal received in accordance with a reception control signal is assigned to the receiver, a CPU for fetching a message following the calling signal determined to be assigned to the receiver by the address comparators, a message memory for storing a received message, and a display for displaying the message stored in the message memory. The card-like ROM stores at least a part of the reception control data and supplies the reception control data to at least one of the reception controller and the address comparator. The reception control data includes at least one of a frame number representing a frame to be received, an address for receiving a message, and remaining reception number data representing the number of times capable of receiving contract information.
In the paging receiver of U.S. Pat. No. 5,0,19,874, the CPU checks whether a received address coincides with addresses set in address registers of a first group or addresses set in address registers of a second group. Received address type information, message, and reception time are stored in a normal message memory or a contract information memory in accordance with a result of the check on the received address by the CPU.